The severity of neurofibromatosis 1 and its variable expressivity make prenatal diagnosis appealing. We conducted our research to assess patient characteristics associated with the desire for prenatal diagnosis. Between 1995 and 2004, 361 neurofibromatosis 1 adult patients were interviewed about their desire for prenatal diagnosis. Answers were classified in three groups: (1) no; (2) uncertain; (3) yes. Socio-demographical and clinical data were analyzed by logistic multinomial regression for their association with the desire for prenatal diagnosis. Male-to-female sex ratio was 0.93. Mean age at study ± SD was 33.5 ± 10. Seven four patients (20.5%) would consider prenatal diagnosis; 240 (66.5%) did not; and 47 (13.0%) were uncertain. In multivariate analysis, compared to the no group, a longer follow-up (OR = 1.25 [1.11-1.41]), a younger age at study time (OR = 1.25 [1.11-1.41]), not having child (OR = 2.46 [1.03-5.97]) and a higher educational level (OR = 5.07 [1.05-24.47]) were independently associated with the yes group. Compared to the no group individuals who were in the uncertain groups were younger (0.95 [0.90-0.99]), less often married (0.11 [0.01-0.89]) and had a longer follow-up (1.26 [1.09-1.46]). There is a significant demand for prenatal diagnosis among neurofibromatosis 1 French patients. This demand is associated with individuals who are younger, have no child, have a longer follow up, and higher level of education.